Method of steam-treating sanitary systems and/or for disinfecting the pipelines of sanitary systems and whirlpool system for implementing the method

ABSTRACT

A whirlpool system includes a basin defined by basin walls; a pipe system including a central conduit and nozzles coupled to the central conduit and situated in the basin walls and having nozzle outlets directed to the basin; a pressure generator coupled to the central conduit for supplying the nozzles with water and/or air; a mist generator for generating a fluid mist under influence of temperature at normal atmospheric pressure; and an intake conduit coupling the mist generator to the central conduit in a zone of the pressure generator for disinfecting the pipe system and the basin.

BACKGROUND OF THE INVENTION

The invention relates to a method of steam-treating sanitary systemsand/or for disinfecting the pipelines of sanitary systems, particularlythe pipelines in whirlpool systems.

The disinfection of the pipelines of whirlpool tubs has in the past beeneffected, depending on the structural type, either during filling of thetub, in which case, during the filling process, part of the fresh waterwas reversed to flow out of the tub through the pipe system directlyinto the drain pipe. By placing shut-off valves at the whirlpoolnozzles, it additionally became possible to rinse the pipeline systemfor a short time under pressure with the aid of the circulating pump,with the water then not being discharged from the pressure side into thetub but into the drain pipe (DE-OS [German Unexamined Published PatentApplication] 3,420,714).

In other methods, fresh water mixed with a disinfectant is conductedthrough the pipe system practically without pressure at the end of thebath immediately after the bath water has been emptied. In this case,however, there exists the drawback, on the one hand, that relativelylarge quantities of fresh water are required and, on the other hand, thewater mixed with the disinfectant also enters the interior of the tub.In this method, a second step is required in which the entire pipesystem including the interior of the tub must be carefully rinsed withpure fresh water in order to avoid skin irritation during the next bath(DE-OS 3,722,281).

Finally, it has been attempted to design tightly closable nozzles withwhich the flow direction can be reversed to flush the pipe system withthe aid of the circulating pump under the full pumping pressure so thatthe mechanical effect of the flowing water is utilized here to preventthe formation of deposits in the pipe system. The problem in thisconnection is, in particular, that it is not possible for the flowingwater to have an influence in the region of the closing mechanisms forthe nozzles (German Patent 3,902,117).

It is known from FR 2,603,976.A1 to generate hot steam for household usein a pressure container and to blow the steam out at its intendedlocation. By spraying in a liquid, the temperature is then reduced andthe quantity of hot steam to be generated is reduced.

SUMMARY OF THE INVENTION

It is now the object of the invention to create a method fordisinfecting pipe systems, particularly the pipes of whirlpool systems,with which the above-described drawbacks are avoided.

This is accomplished according to the invention in that a heated,mist-like fluid medium is produced and introduced into the chamber to besteam-treated or is conducted through the pipe system.

The term "mist-like medium" in the sense of the present inventionincludes a vapor generated with the aid of a liquid under the influenceof temperature, particularly a wet steam or a saturated steam, also awet steam or saturated steam that is introduced into a carrier stream aswell as a fog or an aerosol, that is, a liquid in ultra-fine dispersionthat is introduced into a heated carrier gas. Surprisingly it was foundthat, for example, a pipeline contaminated with Pseudomonas aeruginosawas free of bacteria after being charged with steam as the mist-likemedium at a temperature between 70° and 90° C. for a period of only afew minutes.

The particular advantage of this method is that, instead of largequantities of flushing water and the use of chemicals, only a smallquantity of liquid and small amounts of energy are required to producethe mist-like medium. In a simple manner, the mist-like medium may herebe conducted through the entire pipe system and thus flow freely throughthe swirl nozzles into the interior of the tub as well as through thepressure conduit, the circulating pump and the suction opening into theinterior of the tub. Thus all regions of a whirlpool tub critical forcontamination are subjected to the influence of the heated mist-likemedium.

As one feature of the method according to the invention, the mist-likemedium is produced by vaporizing a liquid under the influence oftemperature. For this purpose, water, preferably demineralized water, isprimarily employed. As a further feature of the method according to theinvention, a vaporization process that takes place under normalatmospheric pressure is preferred. This has the advantage that anelectrically heated steam generator operating without pressure can beemployed to produce the mist-like medium, since low steam power isrequired to solve the task at hand. The advantage is here that suchsteam generators do not include pressure vessels and consequently arenot considered to be steam kettles in the technical sense. The flowthrough the pipe system is here effected by the volume displacementproduced by the steam generator. A particular advantage of the use ofhot steam is that the water is sterilized by the vaporization process sothat no new germs are introduced into the pipe system from the outsideeven if the generated steam is introduced into the pipe system at atemperature of less than 100° C. Another advantage of this manner ofproceeding in the treatment of whirlpool systems is that, instead of 30to 40 liters of water, as was required in the past to flush the pipesystems, possibly with the addition of disinfectants, only a waterquantity of between 1 and 3 liters, depending on the size of the system,is required.

As another feature of the method according to the invention it isprovided that the mist-like medium is produced in that a liquid inultra-fine dispersion is introduced into a carrier gas to form anaerosol. This manner of proceeding provides the opportunity that thevolume stream required to create a flow through the pipe system is madeavailable by the carrier gas, with the flow velocity possibly beingproduced by way of an appropriate pressure generator, for example, ablower. The fluid is introduced into the carrier gas stream inaccurately measured quantities and in ultra-fine dispersion. Thetemperature level required for disinfection for the mist-like mediumthat has been formed by spraying liquid into the carrier gas can beattained, as a feature of the invention, in that the carrier gas isheated before the aerosol is formed. However, depending on the quantityof liquid sprayed into the carrier gas stream per unit time, thetemperature of the carrier gas stream must be made higher because thespraying in of the liquid results in a reduction of the temperature inthe manner of vaporization cooling. However, it is possible to set thetemperature level precisely so that the resulting mist-like medium canbe introduced into the pipe system at a precisely predeterminedtemperature.

Another feature of the invention provides that the resulting aerosol isheated before being introduced into the pipe system. Depending on theconfiguration of the temperature control and the quantity control forthe liquid to be sprayed in, this method step can also be combined withthe preceding method step, that is, the heating of the carrier gasstream before the aerosol is formed. It is, however, particularlyadvisable for the liquid to be sprayed onto a preferably temperaturecontrollable vaporizer surface. This has the advantage that, on the onehand, the carrier gas stream is heated and the vaporization energy isnot generated by the carrier gas stream but by the vaporizer surface.The prior spraying or atomization of the liquid accelerates thevaporization and permits better regulation.

However, if water is employed to generate the mist-like medium byforming an aerosol, care must be taken that the water itself is free ofgerms since in this manner of proceeding temperatures generally liebelow the boiling temperature of water so that the disinfection of theemployed liquid itself during the aerosol forming process is not assuredwith the same reliability as this is the case if the mist-like medium isgenerated from steam.

As another feature of the method according to the invention, it isprovided that the liquid for generating the mist-like medium is atemperature resistant disinfectant, at least as an addition to water.This feature of the method has the advantage that in addition to thethermal action a chemical action also takes place. This is particularlyadvisable if the maximally permissible temperature is limited by thematerial of the surfaces to be disinfected, for example, a temperatureof 80° C. must not be exceeded, although it can be expected that germsare present which are not reliably killed at this temperature level.However, it is a prerequisite that the disinfectant does not chemicallydecompose when heated to such temperatures. Another prerequisite is thatthe disinfectant employed, when in its vapor form, also when mixed withsteam, is not a health risk if inhaled.

The invention further relates to a whirlpool system for implementing themethod according to the invention. The system includes a basin whosewalls and/or bottom are equipped with nozzles for the introduction ofwater and/or air and which are connected by way of pipelines with atleast one pressure generator in order to charge the nozzles with waterand/or air. Such a whirlpool system, which is usually constructed in theform of a tub, employs a circulating pump which sucks water from theinterior of the tub through a suction line and then presses the waterinto the filled interior of the tub through a pressure conduit withwhich are connected a plurality of nozzles that are directed toward theinterior of the tub. The water jet may additionally suck in air throughthe nozzle so that a jet composed of a mixture of water and air entersinto the interior of the tub. Instead of such swirl nozzles, or also inaddition to such swirl nozzles, nozzles that are connected with a blowerby way of a pressure conduit may be arranged, preferably in the bottomregion, so that air is introduced from the bottom through a plurality ofnozzles into the filled tub. This pipeline system which is itselfcharged only with air comes in contact with the contents of the tub whenthe pressure generator is switched off and/or when, at the end of thebath, the tub is drained, with part of the tub water then being emptiedinto the drain pipe through the air conduits which are locked relativeto the drain pipe by means of a valve.

According to the invention it is provided for such a whirlpool systemthat an intake conduit opens into a central pressure and/or suctionconduit in the region of the pressure generator and is connected with adevice for generating a heated, mist-like fluid medium. With the aid ofsuch an arrangement it is possible to conduct the heated mist-likemedium through the entire pipeline system including the circulatingpump, with the medium being able to flow out of the nozzle openings aswell as out of the suction openings of the circulating pump and out ofthe pure air nozzles disposed in the bottom. Thus it is ensured that allcomponents that have had contact with the used bath water and which arenot manually accessible are exposed to the disinfecting effect of theheated, mist-like medium. Care must merely be taken that the opening ofthe pressure conduit of the pressure generator is blocked against airfor the disinfection process by way of a blocking device since thepressure generator for the air is generally followed directly by anelectrical heating cartridge which must not come in contact with themist-like medium. However, on the other hand, this cartridge is alsoarranged in such a manner that in this region the pressure conduit doesnot come in contact with the used bath water at any time.

As an expedient feature of the invention it is provided that the devicefor producing the mist-like medium is formed by a steam generator. Thesteam generator is here advisably configured in such a way that itoperates without pressure, that is, it is only under atmosphericpressure, with the flow through the pipelines being effected exclusivelyby enlargements of volume within the steam generator and thus bydisplacement. However, if a steam generator is employed and water isused to produce the mist-like medium, care must be taken that allcomponents coming in contact with the mist-like medium are made ofmaterials which are reliably able to withstand temperature charges of100° C.

In another feature of the invention, a device is provided for producingthe mist-like medium. This device is characterized by a housing that isconnected to the intake conduit and is equipped with at least oneheating device for heating blower air and is in communication with ablower. At least one spray device for generating ultra-fine dropletspreferably opens into the housing in the region of the heating device.The opening of the spray device into the intake conduit may also beprovided, when seen in the direction of air flow, either upstream of theheating device or downstream of the heating device. If required, asecond heating device may be provided to simplify control. In that casethe liquid is sprayed into the heated air and then the heated mist-likemedium is heated further by means of a second heating device up to itsfinal treatment temperature.

Preferably, one feature provides that the spray jet is directed toward avaporizer surface of the heating device. This accomplishes that thecarrier gas stream, that is, the air introduced by way of a blower, canbe heated and that the heating energy required for the vaporization isnot taken away from the carrier gas again but is introduced directlyover the vaporizer surface into the sprayed-on liquid so that there willbe a very rapid vaporization in the manner of a film vaporization.

Since only a small stream of carrier gas is required to convey thefogged medium, for example, through a pipeline system, it isparticularly advisable for the spray jet to be generated by way of apressure-free mechanical atomization, for example, by way of a so-calledoscillatory atomizer.

The invention will now be described in greater detail for an embodimentthereof and with reference to schematic drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a whirlpool tub equipped with steam disinfection;

FIG. 2 depicts a device for generating a heated mist-like medium.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The whirlpool tub 1 only indicated in FIG. 1 is provided in its sidewalls with a plurality of swirl nozzles 2 which are in communication byway of a pressure conduit 3 with the pressure conduit 4 of a circulatingpump 5. Circulating pump 5 is connected by way of a suction line 6 witha combined intake-discharge opening 7 disposed in the bottom of the tub.The combined intake-discharge opening is configured in such a way thatduring operation water is sucked in through suction conduit 6 from theinterior of the tub and is re-introduced through swirl nozzles 2 intothe filled tub interior below the surface of the water. If the drainopening is opened, the water is able to drain completely into drain pipe8 from the interior of the tub as well as from the pipe system composedof pipe conduit 3, pressure conduit 4 and suction conduit 6.

Swirl nozzles 2 are also connected to an air duct 9 which includes anadjustable suction opening 10 disposed in the region of the tub edge sothat, during operation of circulating pump 5, air is sucked in by thewater jet coming out of swirl nozzles 2 and a jet composed of awater-air mixture is pressed into the interior of the tub.

Once the bath is completed, drain opening 8 is opened permitting thewater to drain out completely.

By way of an intermediary check valve 11, a pipe conduit 12 is nowconnected with pressure conduit 4 and with a device 13 for producing aheated, mist-like medium, for example, with an electrically heatablesteam generator 13. As soon as the tub and its pipe system are empty,the check valve is opened and the steam generator is put into operation.The steam generated in the steam generator is now pushed through pipeconduit 12 into pressure conduit 4 of the pipe system and then flowsthrough pipe conduit 3 and swirl nozzles 2 into the interior of the tub.However, flow resistance causes part of the steam to flow in through thecirculating pump, which is configured as a rotary pump, and throughsuction conduit 6 into the now open intake-discharge fixture 7 and isthus able to also flow out of the open drain opening in the tub bottom.

In this way, all regions of the pipe system including the nozzleopenings and the circulating pump are touched by steam so that germsremaining in the pipeline system from the used bath water are killedalready after a short time. If the tub is appropriately made ofmaterials which are temperature resistant up to a range of, for example,above 100° C., the initial steam temperature employed may be 100° C., inwhich case even the swirl nozzles most remote from the point ofintroduction are soon subjected to a temperature of more than 90° C.,thus ensuring that any existing germs will reliably be killed.

In this connection it must be considered that generally the fittings andnozzles associated with such a pipe system are made of plastics whichare able to resist temperature stresses up to somewhat more than 100° C.

For this purpose, the steam generator 13 requires a connected electricalpower of a maximum of 3 KW, with it being necessary to vaporize aquantity of water of no more than 3 liters for proper disinfection.

In embodiments which, in addition to or instead of swirl nozzles 2, arealso equipped with bottom nozzles through which only air is introduced,an appropriate connection for the steam generator 13 to thisair-carrying conduit must be provided immediately downstream of theblower so that these conduits which come in contact with the water whenthe blower is turned off, or also during emptying, are also exposed tothe hot steam.

For both embodiments it may be advisable if an additional fresh waterconnection is provided so that the pipeline system can be flushed withfresh tap water immediately after the used bath water has been drainedto flush out in this way initially mechanically any deposits such asskin scale, soap and dirt residues or the like. The conduits which arethus flushed with clear water practically without pressure are thencharged with steam as the mist-like medium as described above.

FIG. 2 shows a special embodiment of device 13. This device includes avaporizer chamber 14 in which a heatable vaporizer surface 15 isdisposed. The outlet of a blower 16 opens into this vaporizer chamber 14so that air as the carrier gas is able to flow through vaporizer chamber14. The outlet 17 of vaporizer chamber 14, which can be blocked by meansof a shut-off valve 11, is connected to the system to be steam treated,for example the whirlpool tub shown in FIG. 1.

At least one spraying device 18 whose spray jet is directed towardvaporizer surface 15 opens into vaporizer chamber 14. To simplifyquantity regulation, two spray devices 18 are provided here. These maybe configured either as compressed air spraying devices, but preferablyas pressure-free mechanical sprayers, for example as oscillatingatomizers. In this embodiment, the liquid to be atomized is supplied tothe system from a container disposed at a higher location or, as shownhere, by means of a conveying pump 19 from a vessel 20. By way of anautomatic controller 21, which is in communication with the energysupply for oscillating atomizer 18, it is ensured that the atomizer canbe switched on only if the intake conduit is filled and is turned off ifthere is no water. The quantity regulation for an oscillating atomizercan be realized directly by an adjustment of the amplitude of theoscillating member.

The temperature of vaporizer surface 15, on the one hand, and theresulting mist-like medium, on the other hand, is detected by way oftemperature sensors 22 and 23 and serves to regulate the quantity ofliquid to be supplied and/or the temperature of the vaporizer surface sothat the desired temperature can be maintained and/or overheating isimpossible. If a higher temperature is desired in the steam treatmentregion, this can be accomplished by way of correspondingly heating thecarrier gas, in which case, however, the sprayed-in liquid is dischargedno longer as a visible mist or steam in the physical sense.

The device described in connection with FIG. 2 may also be employed tosteam-treat other sanitary systems. If the heating and vaporizer outputas well as the atomizer output are configured appropriately, use tosteam treat a sauna cabin is also possible since here again thetemperature must remain within a maximum permissible range.

I claim:
 1. A method of disinfecting sanitary systems, comprising thesteps of generating a heated fluid mist by vaporizing a liquid underinfluence of temperature at normal atmospheric pressure and applying thefluid mist to a surface to be disinfected.
 2. The method as defined inclaim 1, wherein the sanitary system includes a pipe system and furtherwherein the step of applying the fluid mist comprises the step ofpassing the fluid mist through the pipe system.
 3. The method as definedin claim 2, wherein the sanitary system includes a whirlpool system andfurther wherein the step of applying the fluid mist comprises the stepof exposing whirlpool system components to the fluid mist.
 4. The methodas defined in claim 1, wherein the step of generating the fluid mistcomprises the step of introducing a liquid in ultra-fine dispersion intoa carrier gas for forming an aerosol.
 5. The method as defined in claim4, further comprising the step of heating the carrier gas prior to thestep of introducing.
 6. The method as defined in claim 4, furthercomprising the step of heating the carrier gas during the step ofintroducing.
 7. The method as defined in claim 4, further comprising thestep of heating the aerosol prior to applying the aerosol to a surfaceto be disinfected.
 8. The method as defined in claim 4, furthercomprising the step of regulating the quantity of the liquid prior tothe introduction thereof into the carrier gas as a function of thetemperature of the fluid mist.
 9. The method as defined in claim 1,wherein the step of generating the fluid mist comprises the step ofspraying the liquid onto a vaporizer surface and exposing the vaporizersurface to a carrier gas.
 10. The method as defined in claim 9, furthercomprising the step of heating the carrier gas prior to the step ofspraying.
 11. The method as defined in claim 9, further comprising thestep of heating the carrier gas during the step of spraying.
 12. Themethod as defined in claim 1, wherein the liquid is germ-free water. 13.A whirlpool system comprising(a) a basin defined by basin walls; (b) apipe system including a central conduit and nozzles coupled to thecentral conduit and situated in the basin walls; the nozzles havingoutlets directed to the basin; (c) a pressure generator coupled to saidcentral conduit for supplying the nozzles with at least one of water andair; (d) mist generating means for generating a fluid mist underinfluence of temperature at normal atmospheric pressure; and (e) anintake conduit coupling said mist generating means to said centralconduit in a zone of said pressure generator for disinfecting the pipesystem and the basin.
 14. The whirlpool system as defined in claim 13,wherein said mist generating means comprises a vapor generator operatingat normal atmospheric pressure.
 15. The whirlpool system as defined inclaim 13, wherein said mist generating means comprises(a) a housingcoupled to said intake conduit; (b) a blower communicating with saidhousing for generating an air stream passing through said housing; (c) aheating device communicating with said housing for heating said airstream; and (d) a spraying device for generating a jet of fine liquiddroplets; said spraying device opening into said housing in a zone ofsaid heating device.
 16. The whirlpool system as defined in claim 15,wherein said heating device comprises a vaporizer surface and furthercomprising means for directing the jet of fine liquid droplets againstsaid vaporizer surface.
 17. The whirlpool system as defined in claim 15,wherein said spraying device comprises a pressure-less mechanicalatomizer.
 18. The whirlpool system as defined in claim 17, wherein saidatomizer is an oscillating atomizer.
 19. The whirlpool system as definedin claim 15, wherein said mist generating means further comprises aregulating means for varying one of the temperature of the heatingdevice and quantities of the liquid from which the fine liquid dropletsare generated; said regulating means comprising a first temperaturesensor situated at said heating device for sensing a temperature thereofand a second temperature sensor situated in said intake conduit forsensing a temperature of said fluid mist flowing therein.